The basic principles of Evidence Based Medicine
A webpage explaining the foundations of systematic reviews.Key Concepts addressed:
- 2-9 Reviews of fair comparisons should be systematic
- 2-12 Single studies can be misleading
- 2-8 Consider all of the relevant fair comparisons
- 2-1 Comparisons are needed to identify treatment effects
- 2-2 Comparison groups should be similar
Do you know the trick with the spoon and the champagne bottle? A spoon put into an opened champagne bottle is supposed to keep the champagne fresh and bubbly for longer. But is there any truth to this? And what does this have to do with evidence-based medicine?
The editors of a scientific journal tested this theory in a simple experiment many years ago. To do this, they put not just one, but two, half-empty open bottles in a refrigerator overnight: one with a spoon, one without.
Over the course of the next few days, they had volunteers sample both bottles several times, without telling them which one contained the spoon. This way, if the volunteers believed in the spoon’s effect, this wouldn’t influence their judgment. The first finding was that the champagne stayed drinkable for a surprisingly long time, taking more than four days to go flat. The second finding was that the participants could not tell the difference between champagne from a bottle with a spoon and from one without. Both bottles went flat equally fast.
Such a simple experiment, with such a clear answer: we might get the impression that a spoon keeps the champagne fresh because the champagne would have stayed fresh for a surprisingly long time anyway.
So what does this experiment have to do with health care? Read more